Add sidekiq sinatra app for watching queues.
Add SauceLabJobWorker.

Make sure to convert option keys to symbols in SauceLabsWebdriverJob
since sidekiq marshals to/from JSON.
Make SauceLabsWebdriverJob more robust.

* Hide passed tests by default.
* Timeout if more than 60 seconds pass between assertions (instead of
  total time)
* Use driver.get url instead of driver.navigate.to.